Method for forming a pneumatic tire

Abstract

A tire with a changing tread pattern is formed by first forming a tire having a tread, the tread having at least one circumferential or lateral groove. Formed separately is a wearable filler, the wearable filler having a configuration corresponding to at least a portion of the circumferential or lateral groove formed in the tire. After both the tire and the wearable filler have been cured, the wearable filler is located in the radially outer portion of the circumferential or lateral groove or a portion of the circumferential or lateral groove, and secured within the grooves so as to create a groove void radially inward of the wearable filler, the void being exposed upon wear of the tire tread.

1. A method for forming a tire, the tire comprising a tread having a non-skid depth d, the tread comprising tread elements separated by a tread groove and a circumferential or lateral groove in a least one of the tread elements, wherein a wearable filler is located in the radially outer portion of the circumferential or lateral groove or a portion of the circumferential or lateral groove, a groove void being created radially inward of the wearable filler, the void being exposed upon wear of the tread, the method comprising the following steps:
 a) forming a green tire; the green tire having; a tread 
 b) curing the tire, the cured tire tread comprising tread elements separated by a tread groove and a circumferential or lateral groove in at least one of the tread elements; each of the tread groove and the circumferential or lateral groove having the non-skid depth d 
 c) forming a wearable filler; the filler having a configuration corresponding to at least a portion of the circumferential or lateral groove formed in the tire; 
 d) curing the wearable filler; 
 e) securing the wearable filler in the cured tire tread in the radially outer portion of at least a portion of the circumferential or lateral groove of the tire such that the radially outer surface of the wearable filler is substantially flush with the ground contacting surface of the at least one tread element, thereby creating a groove void exposable upon wear of the tread. 
 
   
   
     2. The method of  claim 1  wherein a plurality of wearable fillers are secured in the tire tread. 
   
   
     3. The method of  claim 1  wherein the wearable filler is formed by extrusion, molding, or stamping. 
   
   
     4. The method of  claim 1  wherein the wearable filler is formed as a long strip. 
   
   
     5. The method of  claim 1  wherein the wearable filler is formed with different thickness portions. 
   
   
     6. The method of  claim 1  wherein the wearable filler is mechanically secured in the tire tread. 
   
   
     7. The method of  claim 1  wherein the wearable filler is chemically secured in the tire tread. 
   
   
     8. The method of  claim 1  wherein the wearable filler is secured to the tread by both mechanical and chemical securing means. 
   
   
     9. The method of  claim 1  wherein the wearable filler is cold vulcanized to the tire tread. 
   
   
     10. The method of  claim 1  wherein the method of securing the wearable filler to the tire tread involves the steps of
 a) applying a green curable compound to either the wearable filler or to the portion of the circumferential or lateral groove into which the wearable filler is to be secured; 
 b) hot vulcanizing the tire to cure the green curable compound. 
 
   
   
     11. The method of  claim 1  wherein the wearable filler is secured to the tire tread by means of an adhesive selected from the group consisting of cyanoacrylates, isocyanates, cholorprenes, polyurethane resins, and thin layers of uncured elastomer. 
   
   
     12. The method of  claim 1  wherein the wearable filler is secured to the tire tread by means of an adhesive selected from the group consisting of a solvent based adhesive, a water-based emulsion adhesive, or a solvent-less based adhesive. 
   
   
     13. The method of  claim 1  wherein the wearable filler is secured to the tire tread by means of a retread adhesive. 
   
   
     14. The method of  claim 1  wherein the circumferential or lateral groove formed in the tire has a radially outer portion width WU greater than a radially inner portion width WL, forming a step portion in the groove.